en لیزرهای نیم‌رسانا Semiconductor Lasers پژوهشي Research <span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Quantum cascade lasers (QCLs) are sources in mid-infrared and terahertz (THz) regions used in the sensing domain and quality control. <span style="background:white">This paper investigates QCLs subject to filtered phase-conjugate feedback (FPCF). Instabilities can be detected using the graphical method of pole analysis and the particle swarm optimization algorithm, which allows us to identify and characterize the limitation and critical relations between the laser operating parameters.</span> There is good agreement between the two methods to stability boundaries. The effects of FPCF in comparison with conventional optical feedback (COF), phase-conjugate feedback (PCF), and tilted optical feedback (TOF) show that the penetration time factor has a significant and greater influence on the stability of QCL subject to FPCF. These results are in perfect agreement with previous experimental and analytical studies. </span></span> Quantum cascade laser, stability, Pole analysis, PSO algorithm 19 32 http://ijop.ir/browse.php?a_code=A-10-386-2&slc_lang=en&sid=1 Fahime Bakhsheshi f.bakhsheshi@urmia.ac.ir 10031947532846005426 10031947532846005426 No Department of Physics, Faculty of Science, Urmia University, Urmia, Iran Khosro Mabhouti kh.mabhouti@urmia.ac.ir 10031947532846005427 10031947532846005427 Yes Department of Physics Education, Farhangian University, Tehran, Iran Rahim Naderali r.naderali@urmia.ac.ir 10031947532846005428 10031947532846005428 No Department of Physics, Faculty of Science, Urmia University, Urmia, Iran Ali mahmoodlou a.mahmoodlou@cfu.ac.ir 10031947532846005429 10031947532846005429 No Department of Physics Education, Farhangian University, Tehran, Iran